| 摘要 |
PURPOSE:To obtain a good beam shape, by applying a prescribed driving waveform having an optimum frequency characteristic to each element of a divided transducer. CONSTITUTION:The signal generated from a drive signal generating part D is filtered in filters FL1 and FL2 and is supplied to gain adjusting equipments G1, G2, and G1'. The gain adjusting equipment G1 connected to a transducer E2 on the outside circumference through an amplifier Ampl supplies the output to the gain adjusting equipment G1' also. The gain adjusting equipment G1' is operated to enhance the gain near a frequency f1. Output signals of these gain adjusting equipments G1' and G2 are added in an adding circuit AD. Thus, the signal which is given from the adding circuit AD to a transducer E1 in the inside through an amplifier Amp2 is driven with a gain which is higher than that of the transducer E2 in the outside by components corresponding to the output gain of the gain adjusting equipment G1'. |
